Today, telecommunication traffic between two end points (e.g., two individual telephone subscribers) passes over one or more networks. Each network comprises at least one, and typically a plurality of trunk groups, each group comprising one or more copper cables, optical fibers, or radio channels. The trunk groups run between hubs, each hub comprising at least one telecommunications switch for connecting traffic to another hub. The process by which each switch selects an individual trunk group (i.e., a switched pair of conductors or a time slot within a multiplexed signal on a fiber or on a radio channel) is known as routing.
The decision made by each switch to route calls on a particular trunk group involves a variety of factors. Obviously, trunk operability is crucial to any decision to route traffic across a particular trunk group. Trunk bandwidth is also important since some classes of calls require higher bandwidth than others. Trunk length may be important since it is generally desirable to route calls along the shortest path. The cost associated with routing a call across a trunk may also be important since the lowest cost path is usually desirable.
The switches within an individual telecommunication network may employ one or more well known routing techniques to route calls pursuant to the factors discussed above. Intra-network routing strategies are not necessarily applicable for calls that pass from one network to another. Often, different networks are maintained by different entities. Timely information may not be available outside a network regarding the parameters necessary for the routing of calls thereto. As a result, calls routed to a recipient network may not be completed because of call blockage or congestion, leading to loss of revenue and customer dissatisfaction.
Thus, there is a need for a technique for routing calls between networks that maximizes call completions.